Agree that it could have been a legitimate mistake. After all, mistakes do happen.
However, IMO (I'm not a marksman) a would-be assassin is unlikely to accomplish the damage (even as stated in WC) to two human beings (in mere seconds) with a faulty, slow-to-manipulate, mail-order rifle that had a less-than-desirable-scope mounted on it. LHO was in the USMC, thus, he would know the difference between a crap weapon and one that worked well. Even if he wasn't an accomplished shooter on a range while in the USMC.
Some of the leaps the citizenry are forced to take in accepting LHO as the lone shooter is just incredible.
While on the subject of incredible leaps, I was always curious as to how the hell a former USMC member denounces the US, moves to Russia, marries a Russian gal and hangs out in the USSR for a period of time, then gets a US Government loan to come back to the US? All during the ever-escalating Cold War period.
I guess the US Government just felt "really bad" for the former Devil Dog and let him come home, right? Perhaps I am mistaken and there are other examples of such instances?